Features Made of PTFE material, non-toxic, high / low temperature resistant. Strong magnetic, accurate size, stable performance. Applicable for school laboratory, biochemistry, scientific research, etc. Resistant to strong acids, alkalis, various organic solvents. These stirring bars work with a magnetic stirrer. Specification: Item Type:C Type Stirring Bar Material: PTFE Length Diameter Quantity 10 mm 4 mm 1 item 15mm 6mm 1pcs 20mm 6mm 1pcs 25mm 7mm 1pcs 30mm 7mm 2pcs 35 mm 8 mm 1 item Features: Strong magnetic, accurate size, stable performance. These stirring bars work with a magnetic stirrer. Made of PTFE material, non-toxic, resistant to high and low temperatures. Resistant to strong acids, alkalis and various organic solvents. Applicable for school laboratory, biochemistry, scientific research, etc. Package list: 7 x Stirring Bars Package List